The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
In known applications such as cooking grills in commercial environments, a relatively large mass is provided as a cooking surface in order to reduce overall temperature variations during cooking cycles. This large mass, which is typically aluminum or cast iron, provides what is often referred to as thermal inertia, such that placing items to be cooked on a cooking surface of the grill, e.g., a cold hamburger patty or an egg, does not significantly decrease the overall mass temperature.
Many known grill constructions generally include heating elements secured to the underside of a grill. The heating elements are typically tubular or strip heaters and are mechanically clamped and bolted to the underside at spaced intervals. In another known grill construction, tubular heaters are cast into the large mass grill to improve contact between the heating element and the grill and thus provides for improved heat transfer.
Because of the large mass of the grill and because most constructions do not provide intimate contact between the heaters and the grill, it has not been practical or possible for the heating of the cooking surface to respond rapidly to each and every load placed on the cooking surface. Accordingly, the thermal inertia of the grill has been the accepted practice for controlling the temperature at a desired level without significant variations. However, the large mass of the grill results in especially heavy and bulky equipment that must be shipped and set up in commercial cooking environments. Additionally, the amount of energy that is used to heat an entire grill to the desired temperature is considerable, and if the entire cooking surface is not being used, additional amounts of energy are wasted in keeping the temperature of the massive grill at the desired level.
For temperature sensing and feedback to control the temperature of the grill, thermocouples are typically placed in certain areas of the underside of the grill. However, the number of thermocouples that can be employed is limited due to space and cost considerations. Additionally, thermocouples in these applications generally have a relatively slow response time due to their distance away from the surface of the grill. Because of the limited number of temperature sensors, real time verification of actual temperatures along the grill has not been possible with known systems.
Most commercial cooking today is the result of temperature averaging driven by the thermal inertia of the massive grill. The grill is controlled as a single loop so that the entire grill, or large sections of the grill, run at a desired average temperature. Accordingly, there has not been a means by which to efficiently identify exactly what load has been placed on the grill, e.g. hamburger patties, much less a means to easily and automatically determine where the new load has been placed on the cooking surface of the grill.
While control systems exist that can be programmed for specific cooking schedules or temperature profiles, there has been a need for a system that can automatically sense the exact location and type of load introduced, identify the appropriate cooking schedule or temperature profile, and heat just that load according to the appropriate schedule.